<template>
  <div class="spec-preview">
    <img :src="skuindex.imgUrl" />
    <div
      class="event"
      @mousemove="preview"
      @mouseout="show = 0"
      ref="event"
    ></div>
    <!-- 大图 -->
    <div class="big" v-show="show">
      <img :src="skuindex.imgUrl" ref="pre" />
    </div>
    <!-- mask   遮罩层 -->
    <div class="mask" v-show="show" ref="mask"></div>
  </div>
</template>

<script>
export default {
  name: "Zoom",
  data() {
    return {
      show: 0,
      skuImgindex: 0,
    };
  },
  props: ["skuImageList"],
  computed: {
    skuindex() {
      return this.skuImageList[this.skuImgindex] || {};
    },
  },
  mounted() {
    this.$Eve.$on("skuImg", (index) => {
      this.skuImgindex = index;
    });
  },
  methods: {
    preview(e) {
      this.show = 1;
      let x = e.offsetX;
      let y = e.offsetY; //获取鼠标相对于这个触发元素的距离的大小
      // console.log(x, y);
      let maskX = x - this.$refs.mask.offsetWidth / 2;
      let maskY = y - this.$refs.mask.offsetHeight / 2; //获取遮罩层的宽高的一半之后，
      //获取鼠标相对于这个触发元素的距离的大小-遮罩层的宽高的一半=遮罩层距离这个容器的距离了

      if (maskX <= 0) {
        maskX = 0;
      }
      if (maskY <= 0) {
        maskY = 0;
      }
      if (maskX >= this.$refs.event.offsetWidth / 2) {
        maskX = this.$refs.event.offsetWidth / 2;
      }
      if (maskY >= this.$refs.event.offsetHeight / 2) {
        maskY = this.$refs.event.offsetHeight / 2;
      }
      this.$refs.mask.style.left = maskX + "px";
      this.$refs.mask.style.top = maskY + "px";
      this.$refs.pre.style.left = -maskX * 2 + "px"; //这个就是给放大之后的图片的两倍距离移动就是
      this.$refs.pre.style.top = -maskY * 2 + "px";
    },
  },
};
</script>

<style lang="less">
.spec-preview {
  position: relative;
  width: 400px;
  height: 400px;
  border: 1px solid #ccc;

  img {
    width: 100%;
    height: 100%;
  }

  .event {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 998;
  }

  .mask {
    width: 50%;
    height: 50%;
    background-color: rgba(0, 255, 0, 0.3);
    position: absolute;
    left: 0;
    top: 0;
    // display: none;
  }

  .big {
    width: 100%;
    height: 100%;
    position: absolute;
    top: -1px;
    left: 100%;
    border: 1px solid #aaa;
    overflow: hidden;
    z-index: 998;
    // display: none;
    background: white;

    img {
      width: 200%;
      max-width: 200%;
      height: 200%;
      position: absolute;
      left: 0;
      top: 0;
    }
  }

  // .event:hover ~ .mask,
  // .event:hover ~ .big {
  //   display: block;
  // }
}
</style>